Melatonin promotes seminal root elongation and root growth in transgenic rice after germination
Article first published online: 28 MAY 2012
© 2012 John Wiley & Sons A/S
Journal of Pineal Research
Volume 53, Issue 4, pages 385–389, November 2012
How to Cite
Park, S. and Back, K. (2012), Melatonin promotes seminal root elongation and root growth in transgenic rice after germination. Journal of Pineal Research, 53: 385–389. doi: 10.1111/j.1600-079X.2012.01008.x
- Issue published online: 18 OCT 2012
- Article first published online: 28 MAY 2012
- Accepted manuscript online: 3 MAY 2012 12:09PM EST
- Received March 13, 2012; Accepted April 26, 2012.
- root growth;
- seminal root;
- serotonin N-acetyltransferase;
- transgenic rice
Abstract: The effect of melatonin on root growth after germination was examined in transgenic rice seedlings expressing sheep serotonin N-acetyltransferase (NAT). Enhanced melatonin levels were found in T3 homozygous seedlings because of the ectopic overexpression of sheep NAT, which is believed to be the rate-limiting enzyme in melatonin biosynthesis in animals. Compared with wild-type rice seeds, the transgenic rice seeds showed enhanced seminal root growth and an analogous number of adventitious roots 4 and 10 days after seeding on half-strength Murashige and Skoog medium. The enhanced initial seminal root growth in the transgenic seedlings matched their increased root biomass well. We also found that treatment with 0.5 and 1 μm melatonin promoted seminal root growth of the wild type under continuous light. These results indicate that melatonin plays an important role in regulating both seminal root length and root growth after germination in monocotyledonous rice plants. This is the first report on the effects of melatonin on root growth in gain-of-function mutant plants that produce high levels of melatonin.